Controlled release formulations

Abstract

The present invention provides stable, self-assembling, biocompatible and biodegradable hydrogel formulations, into which one or more compounds may be incorporated allowing for delayed release or controlled release of the incorporated compounds as the hydrogel is degraded in the body.

What is claimed is: 
     
       1. A method for transdermal or transmucosal delivery of a therapeutic agent to a subject, comprising contacting an epidermal or mucosa layer of the subject with a composition, the composition comprising:
 a) a therapeutic agent; 
 b) a sucrose ester, wherein the sucrose ester is a combination of sucrose stearate and sucrose distearate; and 
 c) a buffer, 
 wherein the composition is a hydrogel formed by heat treatment of a suspension of (a)-(c) at temperatures between 37-45° C. 
 
     
     
       2. The method of  claim 1 , wherein the composition further comprises a preservative. 
     
     
       3. The method of  claim 2 , wherein the preservative is ethylene diamine tetraacetic acid (EDTA), benzalkonium chloride, sodium azide or dodecyl maltoside. 
     
     
       4. The method of  claim 1 , wherein the composition has a pH from 4 to 8. 
     
     
       5. The method of  claim 1 , wherein the composition has a pH from 4.5 to 6.5. 
     
     
       6. The method of  claim 1 , wherein the therapeutic agent is a peptide, hormone, steroid, anti-inflammatory, anti-biotic, anti-viral, UV blocker, or anti-wrinkle agent. 
     
     
       7. The method of  claim 1 , wherein the therapeutic agent is an anti-wrinkle agent selected from the group consisting of: retinol, retinoic acid, 13-trans retinoic acid, 13-cis retinoic acid, retinyl ester, hydroxy acid, alpha hydroxy acid, beta hydroxy acid, poly hydroxy acid, glycolic acid, lactic acid, an exfoliant, a Coenzyme Q10 copper peptide, a kinetin, a tea extract, and a collagen. 
     
     
       8. The method of  claim 6 , wherein the steroid is testosterone. 
     
     
       9. The method of  claim 6 , wherein the peptide is thymosin β-4. 
     
     
       10. The method of  claim 1 , wherein the buffer is an aqueous buffer. 
     
     
       11. The method of  claim 10 , wherein the buffer is an acetate buffer. 
     
     
       12. The method of  claim 10 , wherein the buffer is a citrate buffer. 
     
     
       13. The method of  claim 1 , wherein the therapeutic agent is uniformly distributed throughout the hydrogel. 
     
     
       14. The method of  claim 1 , wherein the composition is administered to the subject topically, nasally, enterically or orally. 
     
     
       15. The method of  claim 1 , wherein the composition is administered topically via a transdermal device, the device comprising at least a first and a second layer, wherein the first layer is a backing layer and the second layer comprises the composition. 
     
     
       16. The method of  claim 15 , wherein the device comprises a third layer, the third layer comprising a different therapeutic agent than the second layer. 
     
     
       17. The method of  claim 15 , wherein the device further comprises an adhesive.